"Being overweight raises risk of men developing aggressive prostate cancer," The Guardian reports.
This report, which considered the results from 104 studies involving more than nine million men, looked at diet, nutrition, physical activity, weight and the risk of prostate cancer.
It also found strong evidence that being tall - a marker of developmental factors in the womb, childhood and adolescence - increases the risk of prostate cancer.
The report found limited evidence for a link between diets high in dairy products or calcium and an increased risk of prostate cancer, and low blood levels of vitamin E or selenium and an increased risk of developing cancer.
How could obesity lead to prostate cancer?
The report offers two, as yet unproven, hypotheses:
- obesity could change the hormonal make-up of the body, creating an environment favourable to the development of prostate cancer
- obesity could lead to inflammation of the prostate, which could lead to tissue changes that trigger the onset of cancer
Who produced the report?
The report was produced by the World Cancer Research Fund International as part of their Continuous Update Project.
This report aims to update a report from 2007 by analysing global prostate cancer prevention and survival research linked to diet, nutrition, physical activity and weight.
The results were well reported by the media.
What evidence did the report look at?
The report is based on the findings of a systematic review performed by a team at Imperial College London, and its interpretation by a panel of independent experts.
The results from 104 studies were analysed. This included more than nine million men, 191,000 of whom had prostate cancer.
What are the main findings of the report?
The report found strong evidence that:
- being overweight or obese (measured by body mass index [BMI], waist circumference, or waist-hip ratio) increases the risk of advanced prostate cancer (advanced, high-grade, or fatal prostate cancer)
- developmental factors in the womb, childhood and adolescence that influence growth are linked to an increased risk of prostate cancer - for example, taller men are at an increased risk of prostate cancer
- beta-carotene, a pigment found in certain plants and fruits (consumed from diet or supplements), had no substantial effect on the risk of prostate cancer
There was limited evidence that:
- higher consumption of dairy products increases the risk of prostate cancer
- diets high in calcium increase the risk of prostate cancer
- low plasma (blood) alpha-tocopherol concentration (vitamin E) increases the risk of prostate cancer
- low plasma (blood) selenium concentration increases the risk of prostate cancer
The report made no conclusions about whether a number of other factors increased or decreased the risk of prostate cancer. For example:
- cereals (grains) and their products
- dietary fibre
- non-starchy vegetables
- pulses (legumes)
- processed meat
- red meat
- total fat
This is not an exhaustive list. For the complete list, you can download the report for free (PDF, 2.49Mb).
No conclusions were made because the studies identified were either poor quality, their results were inconsistent, or too few studies were identified.
"Being overweight raises risk of men developing aggressive prostate cancer," The Guardian reports. A major new report from the World Cancer Research Fund has found strong evidence obesity increases the risk of aggressive prostate cancer.
Links to Headlines
Being overweight raises risk of men developing aggressive prostate cancer. The Guardian, November 19 2014
Obesity 'raises prostate cancer risk': 10% of cases could be prevented if men kept themselves at a healthy weight. Daily Mail, November 19 2014
Links to Science
World Cancer Research Fund International. Diet, nutrition, physical activity and prostate cancer (PDF 2.49Mb). November 2014
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